In so-called regions exposed to the risk of explosions, for example on offshore drilling platforms, the electrical energy that bears on the outer electronic interfaces of an electrically operated apparatus can ignite a gas/air mixture or a dust/air mixture that is present in the region exposed to the risk of explosions and thus cause said gas/air mixture or dust/air mixture to explode. This to a particular degree applies to highly reactive gas mixtures such as, for instance, mixtures from hydrogen and oxygen, to which said electrical energy is available as an activation energy in order for an exothermal reaction of hydrogen and oxygen so as to form water to be initiated. This applies in a similar fashion to dust/air mixtures such as, for example, carbon dust/air mixtures.
Against this background, it is known from the prior art to provide pressure-resistant housings in which electrically operated apparatuses can be received when the latter are to be used in a region exposed to the risk of explosions.
It often proves disadvantageous in the case of such pressure-resistant housings that the latter are typically embodied so as to be tight in terms of airborne noise. An airborne noise that is generated by a loudspeaker of the electrically operated apparatus can thus not make its way from the housing interior to the outside. Conversely, in the case of a microphone for the detection of noise being disposed in the apparatus, said microphone can also not detect any noise from outside the pressure-resistant housing. In other words, the housing interior that is delimited by conventional pressure-resistant housings is typically acoustically insulated from the external environment of the housing.